N&W's Gas Turbine Electric Locomotive

[NW Mailing List]

The fly ash destroying turbine blades also doomed the UP experimental coal turbine #80 (later #8080).  

Between 1953 and 1956 South African Railways built the Class 25 4-8-4 which included a complex system to condense steam and recirculate it to the locomotive tender to conserve water in the arid region where the locomotives operated. This required a large "fan" below the stack to provide draft because the exhaust steam was being captured.  Unfortunately the fly ash was still coming from the smokebox and devoured the blades.   Subsequent analysis determined that maintenance costs and out of service time far outweighed the cost of hauling one or two auxiliary water cars and the engines were converted back to non- condensing configuration.   The analysis was aided by the fact that SAR also built a group of Class 25NC locomotives that did not include the condensing system, providing a true baseline for comparison. 

Conclusion, small acidic particles at high velocity cause high rates of corrosion. What a surprise. 

Sent from my digital telegraph key
Jim S

> On Jun 17, 2020, at 10:14, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> 
> Norfolk and Western did not operate a coal-fired gas turbine, electric drive
> locomotive but it proposed one. I cover this in my Giant book. N&W did this
> in cooperation with five other railroads, three coal companies and the
> Bituminous Coal Research. The idea was to use pulverized coal and then blow
> it through a nozzle under high air pressure to create talcum powder sized
> particles. This powdered coal is then blown into a combustion chamber to
> create the gases to run the turbine.
> 
> The potential was a very compact engine, high thermal efficiency (about 3X a
> Y-6), eliminated water as medium and a need for a boiler, with few moving
> parts. All started at about the end of World War II and in 1946, N&W
> announced it was proceeding to build two locomotive plants with generators
> from two manufacturers, Allis Chalmers and General Electric. The big problem
> was the fly ash eroding the turbine blades. Even though it was announced in
> 1956 that a locomotive would be built in about two years, it never happened.
> 
> Dieselization was the answer that won out and the fly ash problem was never
> solved.
> 
> Bud Jeffries
> 
>